Outlook Performance Issues

For a vast majority of my users, when Outlook does its first sync of the day, Outlook will spike the CPU for an extended period of time. In addition, the Memory usage in Outlook either spikes, or continually climbs until the sync completes.

The CPU hangs around 90% for single cores and 25% on quads. Memory seems to climb steadily until the sync completes. The average end of the sync stops with memory around 300MB.

This seems to happen for around 10-20 minutes while Outlook gathers all changes made since the last login.

If I open the Send/Receive window to track the progress of the sync, I've also noticed that a download of around 6 MB takes 10-15 minutes.

It seems 5.16 fixes some of these issues, but we are not moving to it for about 2 months. Is there anything we can do in the meantime?